That's mean that this book doesn't fit for one who train in Aikikai or Yoshinkan or Tomiki Dojo?

I train in Ki Aikido, so we're pretty familiar with Tohei Sensei's teachings. I also read "Ki in Daily Life" and found it to be very helpful. We do the tests like the unbendable arm and alike on regular basis. In fact, beside being tested for techniques (kyu and dan ranks), we also have to pass Ki tests that increase in difficulty over the years. But I don't think his teachings are limited to any school of Aikido. Actually they're not even limited to Aikido itself (that is to mean that anyone can benefit from developing Ki and applying these principles to his life, not only those who go to the dojo on regular basis). That's why Tohei Sensei can have Ki seminars for non-aikidoists.

Anyone can practice the excercises described in the book, anyone can try to apply the principles in his daily life. If you're really interested in aikido being your way of life rather than just something you do, then by all means read the book. You might also try and look at this website: "Ki Breathing" by Koichi Tohei Sensei You can find lots of valuable info and things to think about there.